Amprius Technologies Achieves Milestone with Advanced battery Testing

Amprius Technologies, Inc. has recently revealed that an independent testing laboratory has confirmed the performance of its innovative 390 Wh/kg polymer electrolyte cell by successfully completing the nail penetration test.

Applications in Military Technology

The U.S. Army is currently evaluating these cells for multiple uses, especially as part of the Conformal Wearable Battery (CWB), which is designed to be integrated into soldiers’ vests. This battery serves as a vital power source for essential communication and navigation devices.

Testing Standards and Procedures

This test is crucial for assessing the viability of battery technology in combat situations.According to the MIL-PRF-32383 (Military Performance Specification), cells must not ignite or explode, and their external temperature must remain below 338°F (170°C) when subjected to penetration by sharp objects.

During the test, a stainless steel nail with a diameter of 0.113 inches is driven through a fully charged cell at a specified speed. The cell is considered to have passed if there is no smoke or flames produced after the penetration.

Innovative Safety Features

The polymer electrolyte utilized by Amprius effectively prevents the nail from causing a low-resistance short circuit, as evidenced by the minimal rise in cell temperature and only a slight drop in voltage after penetration. Remarkably, the cell continues to operate and supply power, a crucial feature for batteries used in soldier wearables.

Future Developments and Contracts

In October 2021, Amprius secured a contract with the U.S.Army to create lithium-ion batteries featuring a 100% silicon anode. This rapid prototyping initiative, spanning 18 months, focuses on the design, development, and validation of high-energy-density batteries for various military applications, including the CWB.

The U.S. Army has also placed an order for thirty battery packs to demonstrate their capabilities.

“The successful completion of this nail penetration test marks a pivotal advancement in our technology and product development as we strive for increased production capacity,” stated Dr. Ionel Stefan, CTO of Amprius. “We have a unique chance to enhance energy density performance by nearly 100%,effectively doubling the runtime for all mobile-powered devices without adding extra weight to the wearable batteries for our soldiers.”